JP3464291B2 - Motion adaptive luminance signal color signal separation filter and television signal receiving circuit - Google Patents

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a motion adaptive type luminance signal / color signal separation filter and a television signal receiving circuit, and more particularly to receiving a high definition television signal compatible with the existing composite color television signal. The present invention relates to a motion adaptive type luminance signal / color signal separation filter and a television signal receiving circuit.

[0002]

2. Description of the Related Art In recent years, a high-definition television signal system completely compatible with the NTSC system, which is one of the current television broadcasting systems, has been proposed as a so-called second generation EDTV system. In the second-generation EDTV system, the horizontal luminance signal is reinforced in order to improve the horizontal luminance resolution and increase the definition of the image. That is, in the high definition television signal system, the transmission band of the luminance signal (0 to 4.2)
Horizontal frequency component higher than, for example, 4.2 to 6.
The horizontal high-definition signal of 3 MHz is frequency-converted (shifted) to transmit the high-definition television signal multiplexed in the transmission band. The high-definition information inserted in such a composite color television signal is the second generation EDT.
This is one of the features of the V system, and hereinafter, the multiplexed horizontal high-definition signal is simply referred to as an HH signal.

FIG. 14 shows an ED in which HH signals are multiplexed.
It is a figure showing the three-dimensional frequency spectrum distribution of TV signal. In FIG. 14, the μ axis represents a horizontal frequency axis, the ν axis represents a vertical frequency axis, the f axis represents a time direction frequency axis, Y represents a luminance signal, and C represents a color signal. Further, FIG. 14 is a diagram of the three-dimensional frequency space seen from an oblique direction, and FIG.
FIG. 15A is a projection diagram from the positive direction of the μ-axis onto the plane [f−ν] of the time-horizontal frequency axis, and FIG. 15B is a frequency distribution diagram on the horizontal frequency μ-axis.

Generally, in a three-dimensional frequency space, when the motion of an image is large, the luminance signal, the chrominance signal, and the HH signal spread in the time direction, and crosstalk between the three signals may occur. Therefore, it has been proposed that the Y signal, the C signal, and the HH signal are each band-limited on the [f-ν] plane, and that the HH signal is multiplexed with the luminance signal and transmitted only when it is closer to a still image. There is.

FIG. 16 is a block diagram of a conventional motion adaptive type luminance signal / color signal separation filter. In the figure, 1
Is an input terminal for a composite color television signal, 2 is an output terminal for a luminance signal, and 3 is an output terminal for a color signal. The composite color television signal 101 from the input terminal 1 includes an intra-field band pass filter (hereinafter referred to as an intra-field BPF) 12, a frame comb filter 13a, a frame delay circuit 14, a subtractor 17, and a motion detection circuit 8.
Input to 1 respectively. Of these, the 1-frame delay circuit 14 for delaying the composite color television signal 101 is further connected to the frame comb filter 13, the 1-frame delay circuit 15 and the motion detection circuit 81, to which the composite color television signal 101 is connected. Output a 1-frame delay signal. The 1-frame delay circuit 15 is also connected to the motion detection circuit 81 and outputs a 2-frame delay signal.

The motion detection circuit 81 comprises a 1-frame difference detection circuit 82a, a 2-frame difference detection circuit 83 and a maximum value selection circuit 24. Of these, the one-frame difference detection circuit 82a is a subtractor 18a, a horizontal low-pass filter (hereinafter, referred to as LPF) 55, and an absolute value circuit 2.
3a, and a 2-frame difference detection circuit 8
3 comprises a subtracter 19 and an absolute value circuit 23b.
The 1-frame difference detection circuit 82a receives the composite color television signal 101 and the 1-frame delay signal, subtracts these 2 signals by the subtractor 18a, and outputs them to the maximum value selection circuit 24 via the LPF 55 and the absolute value circuit 23a. Outputs motion signals. The two-frame difference detection circuit 83 receives the composite color television signal 101 and the two-frame delay signal, subtracts these two signals by the subtractor 19, and sends the motion signal to the maximum value selection circuit 24 via the absolute value circuit 23b. Is being output. The maximum value selection circuit 24 selects and outputs the larger one of the two motion signals, and uses this as the motion coefficient signal of the motion detection circuit 81.

The outputs of the intra-field BPF 12, the frame comb filter 13a, and the motion detection circuit 81 are input to the mixing circuit 16a, and the output of the mixing circuit 16a is the color signal 10.
Is output from the output terminal 3 and the subtractor 17
Entered in. The output of the subtractor 17 is output from the output terminal 2 as the luminance signal 102. In addition, BP in the field
Regarding the configuration of F12, various filters such as a horizontal comb filter, a line comb filter, a two-dimensional comb filter and a two-dimensional adaptive filter can be used.

Next, the operation of the conventional motion adaptive type luminance signal / color signal separation filter will be described. The motion detection circuit 81 receives the input composite color television signal 101.
In separating the luminance signal and the color signal of (hereinafter, referred to as YC separation), a large motion signal is selected by the maximum value selecting circuit 24 from the outputs of the 1-frame difference detecting circuit 82a and the 2-frame difference detecting circuit 83, and the composite signal is generated. A motion coefficient signal for determining whether the color television signal 101 is a signal representing a still image or a signal representing motion is output to the mixing circuit 16a. Where 1
In the frame difference detection circuit 82a, the 1-frame delay signal and the composite color television signal 101 directly input are subtracted by the subtractor 18a to obtain the 1-frame difference, and L
After passing through the PF 55, the absolute value is obtained by the absolute value circuit 23a to detect the motion amount of the horizontal low frequency component of the Y signal. In the 2-frame difference detection circuit 83, the 2-frame delay signal and the composite color television signal 101 directly input are subtracted by the subtractor 19 to obtain the 2-frame difference, and the absolute value circuit 23b calculates the absolute value. Then, the amount of movement of the Y signal and the C signal is detected.

The amount of motion thus detected is represented by the maximum value selection circuit 24 as a motion coefficient signal in the form of, for example, a motion coefficient k (0≤k≤1). This maximum value selection circuit 24
Then, the motion coefficient signal is controlled so that, for example, k = 0 when it is determined that the input image is a complete still image, and k = 1 when the image is determined as a complete moving image. .

Generally, when the image is a still image,
The inter-frame YC separation calculation is executed by the frame comb filter 13a, and when the image is a moving image, the intra-field BPF 12 performs the intra-field YC separation calculation to extract the C signal. However, when divided into these two, the image flickers in the intermediate state.

Therefore, in the motion adaptive YC separation filter, the intra-field BPF 12 and the frame comb filter 13a are arranged in parallel. Then, with the motion coefficient k corresponding to the degree of motion detected by the motion detection circuit 81, the mixing circuit 16a is caused to perform calculation in the frequency domain according to the following equation (1), and the motion adaptive YC separated C is performed. The signal 103 is output from the output terminal 3.

[0012]   C = k · Cf + (1-k) · CF (1) here, Cf: output value of BPF in field, CF: Output value of frame comb filter, Is.

The subtractor 17 subtracts the motion-adaptive YC-separated C signal 103 from the composite color television signal 101 to obtain the motion-adaptive YC-separated Y signal 10.
2 is output from the output terminal 2.

[0014]

FIG. 17 is a spectrum distribution diagram of the Y signal, the C signal, and the HH signal when the image is stationary in the three-dimensional frequency space. In the conventional motion adaptive YC separation filter, the subtractor 18a of the motion detection circuit 81 extracts the time-frequency region centered at f = ± 15 Hz, and the LPF 55 extracts the time-frequency region together with the C signal multiplexed in the transmission band of the Y signal. The HH signal must be removed. However, in the 1-frame difference detection circuit 82a that detects the amount of movement of the horizontal low frequency component, if the HH signal is multiplexed even if the composite color television signal is a still image, the HH signal component is more than the C signal. Is also inserted in the low range in the horizontal direction, the one-frame difference detection circuit 82a
LPF 55 cannot remove HH signals of 1.9 to 2.1 MHz.

If the HH signal leaking into the horizontal low frequency region which is the motion detection region of the Y signal is detected as the Y signal, the still image is erroneously recognized as a moving image. . For this reason, even though it is a still image, the received YC separation of the composite color television signal cannot be performed optimally because the received composite color television signal is subjected to moving image processing.

The present invention has been made to solve the above problems, and an object thereof is to erroneously detect a component of an HH signal leaking into a horizontal low frequency region as a motion component of a Y signal. To prevent. That is, it is an object of the present invention to obtain a motion adaptive YC separation filter capable of accurately performing motion detection when HH signals are multiplexed and reproducing an image with little deterioration in image quality.

[0017]

A motion-adaptive luminance signal / color signal separation filter according to a first aspect of the present invention is a horizontal high-definition signal (hereinafter, referred to as
It is called HH signal. ) Is multiplexed, the input signal is a high-definition television signal in a motion-adaptive luminance signal / chrominance signal separation filter that YC separates a luminance signal and a color signal from a composite color television signal (high-definition television signal). Identification control signal decoding means for decoding a signal transmitted together with a composite color television signal for identifying whether or not it is present, and intra-field YC separation calculation by band-pass filtering processing of the composite color television signal. If the input signal is a high-definition television signal, an intra-field band-pass filter that performs the above-mentioned operation, a frame comb filter that performs inter-frame YC separation calculation between two composite color television signals with a time difference of one frame, H from the composite color television signal
In order to remove the H signal and the chrominance signal, and otherwise to remove the chrominance signal component from the composite color television signal, the decoded identification control signal is used to detect the horizontal direction.
Switching the pass band that limits the band of the wave number component ,
Motion detection means for detecting the motion amount of the composite color television signal, mixing means for mixing the calculation results of the in-field band pass filter and the frame comb filter based on the motion amount, and the composite color television. And subtraction means for subtracting the output of the mixing means from the John signal to output a luminance signal.

According to a second aspect of the present invention, there is provided the motion adaptive type luminance signal / color signal separation filter according to the first aspect, wherein the motion detecting means is one.
A one-frame difference detection circuit for detecting a first motion coefficient for a one-frame difference signal from two composite color television signals having a frame time difference, and two frames from two composite color television signals having a two-frame time difference 2 to detect the second motion coefficient for the difference signal
It is characterized by comprising a frame difference detection circuit and a maximum value selection circuit for selecting a larger one of the first and second motion coefficients as the motion amount.

According to a third aspect of the present invention, in the motion adaptive luminance signal color signal separation filter according to the second aspect, the one-frame difference detection circuit calculates the one-frame difference signal, and the one-frame difference signal is HH. A horizontal low pass filter (hereinafter referred to as a narrow band LPF) having a pass band set to remove signals and color signals, and a narrow band LPF different from the narrow band LPF to remove color signals from the one-frame differential signal. A horizontal low-pass filter (hereinafter referred to as a wide band LPF) having a pass band set, and when the input signal is a high definition television signal, the output of the narrow band LPF is selected as the first motion coefficient, Otherwise, a selection circuit for selecting the output of the wide band LPF as the first motion coefficient is provided.

A motion adaptive luminance signal / chrominance signal separation filter according to a fourth aspect is the correlation detection circuit according to the third aspect, wherein the one-frame difference detection circuit detects the correlation in the horizontal direction and the vertical direction of the composite color television signal. And the above 1
A difference calculation circuit for calculating a frame difference signal, a horizontal low-pass filter (hereinafter referred to as a narrow band LPF) having a pass band set so as to remove the HH signal and the color signal from the one frame difference signal, and the above. A horizontal low-pass filter (hereinafter, referred to as a low-pass filter in which a pass band different from the narrow band LPF is set so as to remove the color signal from the 1-frame differential signal
It is called a broadband LPF. ), A vertical low-pass filter that band-limits the one-frame difference signal with respect to vertical frequency components, and a two-dimensional low-pass filter that band-limits the one-frame difference signal with respect to horizontal and vertical frequency components, When the input signal is a high-definition television signal, the amount of motion in the direction in which the correlation is strong is determined by the correlation detection circuit from the outputs of the narrow band LPF, vertical low pass filter or two-dimensional low pass filter. Choose as the first motion coefficient, otherwise wideband LPF,
A selection circuit for selecting, as the first motion coefficient, the amount of motion in the direction in which the correlation detection circuit has a strong correlation among the outputs of the vertical low-pass filter or the two-dimensional low-pass filter. To do.

According to a fifth aspect of the present invention, in the motion adaptive luminance signal color signal separation filter according to the third aspect, the one-frame difference detection circuit calculates the one-frame difference signal, and the one-frame difference signal. further from the 1-field delay and two 1 frame difference signal, respectively the composite color television signal in time - second, fourth quadrant of the signal area and HH which Oite color signal into a vertical frequency space <br/> coexist first extraction means for extracting a signal area of the third quadrant, the 1 frame difference signal of a signal area in which the color signal are mixed by a horizontal band-limited, time signals are mixed - the second vertical frequency space, The first horizontal low-pass filter for obtaining the motion component in the fourth quadrant and the one-frame differential signal in the signal area in which the HH signals are mixed are subjected to horizontal band limitation, and time-
The second horizontal low-pass filter for obtaining the motion component in the first and third quadrants of the vertical frequency space, and the first motion amount by adding the motion components by the first and second horizontal low-pass filters. And an adder circuit for outputting as.

A television signal receiving circuit according to claim 6 is
Input to a television signal receiving circuit that receives a composite color television signal (high-definition television signal) in which a horizontal high-definition signal (hereinafter, referred to as HH signal) is multiplexed to obtain a broadband luminance signal and a color signal. An identification control signal for identifying whether the signal is a high-definition television signal, an identification control signal decoding means for decoding a signal transmitted together with the composite color television signal, and a band of the composite color television signal. An in-field band pass filter that performs an intra-field YC separation calculation by a pass filtering process, a frame comb filter that performs an inter-frame YC separation calculation between two composite color television signals with a time difference of one frame, and an input signal are In the case of a high-definition television signal, HH from the composite color television signal No. and the color signal is removed, so that otherwise removing a color signal component from said composite color television signal, the pass band of the band limitation in the horizontal direction of the frequency components by the decoded identification control signal <br / >, A motion detection means for detecting the motion amount of the composite color television signal, a mixing means for mixing the calculation results of the in-field band pass filter and the frame comb filter based on the motion amount. A subtracting means for subtracting the output of the mixing means from the composite color television signal to output a luminance signal; a separating means for separating a color signal and an HH signal from the output of the mixing means; and a separating means for separating the color signal and the HH signal. Demodulating means for demodulating the HH signal and the color signal components separated by the separating means to output first and second color difference signals. Color demodulation means
And a summing unit for adding the demodulated HH signal to the luminance signal and outputting a broadband luminance signal.

According to a seventh aspect of the present invention, there is provided a television signal receiving circuit,
7. The motion detection means according to claim 6, wherein the first motion coefficient for one frame difference signal is detected from two composite color television signals having a time difference of one frame.
2 with a frame difference detection circuit and a time difference of 2 frames
A two-frame difference detection circuit for detecting a second motion coefficient for one frame difference signal from one composite color television signal, and a maximum value for selecting the larger one of the first and second motion coefficients as the motion amount. And a selection circuit.

A television signal receiving circuit according to claim 8 is:
8. The difference calculation circuit according to claim 7, wherein the 1-frame difference detection circuit calculates the 1-frame difference signal;
A horizontal low-pass filter (hereinafter referred to as a narrow band LPF) having a pass band set to remove the HH signal and the color signal from the frame difference signal, and the above-mentioned one to remove the color signal from the one frame difference signal. Horizontal low pass filter (hereinafter,
It is called a broadband LPF. ) And the input signal is a high definition television signal, the output of the narrow band LPF is selected as the first motion coefficient, and otherwise, the output of the wide band LPF is selected as the first motion coefficient. And a selection circuit for performing the selection.

According to a ninth aspect of the present invention, there is provided a television signal receiving circuit,
8. The correlation detection circuit according to claim 7, wherein the one-frame difference detection circuit detects a correlation in the horizontal direction and the vertical direction of the composite color television signal, a difference calculation circuit that calculates the one-frame difference signal, and the one frame. A horizontal low-pass filter (hereinafter, referred to as narrow band LP) whose pass band is set so as to remove the HH signal and the color signal from the difference signal.
It is called F. ), A horizontal low-pass filter (hereinafter, referred to as a wide band LPF) in which a pass band different from the narrow band LPF is set so as to remove a color signal from the 1-frame differential signal, and the 1-frame differential signal is vertical. A vertical low-pass filter that band-limits the frequency component in the direction,
A two-dimensional low-pass filter that band-limits the one-frame differential signal with respect to horizontal and vertical frequency components, and the narrow-band LPF, vertical low-pass filter or 2 when the input signal is a high-definition television signal. Of the outputs of the dimensional low pass filter, the amount of motion in the direction in which the correlation is strong is selected as the first motion coefficient by the correlation detection circuit, and if not, the wide band LPF, vertical low pass filter or two-dimensional Among the outputs of the low-pass filter, there is provided a selection circuit for selecting, as the first motion coefficient, the amount of motion in the direction in which the correlation detection circuit has a strong correlation.

A television signal receiving circuit according to a tenth aspect of the present invention is the television signal receiving circuit according to the seventh aspect, wherein the one-frame difference detecting circuit is
A difference calculation circuit for calculating the 1 frame difference signal, the 1 frame difference signal and further one field and two one-frame difference signal delayed, respectively the composite color television signal in time - Oite the vertical frequency space second to <br/> color signal are mixed, first the signal area and the HH signal of the fourth quadrant are mixed, an extraction means for extracting a signal area of the third quadrant, the signal area of the color signal are mixed The first horizontal low-pass filter for obtaining the motion component in the second and fourth quadrants of the time-vertical frequency space by limiting the horizontal band of the one-frame differential signal and the signal area 1 in which the HH signal is mixed
A second component that limits the horizontal band of the frame difference signal to obtain a motion component in the first and third quadrants of the time-vertical frequency space.
Of the horizontal low-pass filter and an adding circuit for adding the motion components of the first and second horizontal low-pass filters and outputting the sum as the first motion amount.

According to another aspect of the present invention, there is provided a television signal receiving circuit which receives a composite color television signal (high definition television signal) in which a horizontal high definition signal (hereinafter referred to as HH signal) is multiplexed to obtain broadband luminance. In a television signal receiving circuit for obtaining a signal and a color signal, an identification control signal for identifying whether or not an input signal is a high definition television signal, and an identification for decoding a signal transmitted together with a composite color television signal. A control signal decoding means, an intra-field filter for band-pass filtering the composite color television signal, and a time difference of 1 frame.
An inter-frame filter that calculates two composite color television signals, and a signal area component in which color signals in the time-vertical frequency space are mixed is extracted from two composite color television signals having a time difference of one field.
Extracting means for extracting a signal area component in which HH signals in the time-vertical frequency space are mixed from two composite color television signals having a time difference of one field, and the first extracting means. Between an intra-field band pass filter for performing an intra-field YC separation calculation by performing band pass filtering processing on the output of the means, and two composite color television signals with a time difference of one frame extracted from the first extracting means. The interframe Y between the first frame comb filter for performing the interframe YC separation calculation and the two composite color television signals having the time difference of one frame extracted from the second extracting means.
A second frame comb filter for performing C separation calculation; and a calculation means for calculating a difference between two composite color television signals having a time difference of one frame extracted from the first and second extraction means, The HH signal is mixed with the first horizontal low-pass filter that performs the horizontal band limitation of the signal area component in which the color signal is mixed to obtain the motion component in the second and fourth quadrants of the time-vertical frequency space. A second horizontal low-pass filter for obtaining a motion component in the first and third quadrants of the time-vertical frequency space by limiting the horizontal band of the signal domain component, and the first and second horizontal low-pass filters. With a time difference of 2 frames from the first adding means for adding the motion components of
A two-frame difference detection circuit for detecting a second motion amount for a two-frame difference signal from one composite color television signal, and a maximum value selection for selecting the larger one of the first and second motion amounts as a motion coefficient. Means, first mixing means for mixing the output of the intra-field filter and the output of the inter-frame filter based on the motion coefficient, the output of the intra-field band pass filter and the output of the first frame comb filter. Second mixing means for mixing the outputs on the basis of the motion coefficient; multiplying means for multiplying the output of the second frame comb filter and the motion coefficient to generate a high-definition component; Color demodulation means for color demodulating the first and second color difference signals from the output of the mixing means, and demodulation means for demodulating the HH signal from the output of the multiplication means,
It is characterized by further comprising second adding means for adding the HH signal demodulated by the demodulating means to the output of the first mixing means to output a wide band luminance signal.

[0028]

According to the present invention, the motion detecting means removes the HH signal and the color signal mixed in the one-frame difference signal of the composite color television signal in which the HH signal is multiplexed by the identification control signal. Therefore, it is possible to reduce erroneous detection of the motion amount due to the HH signal and the color signal leaking into the motion detection region of the luminance signal.

According to a second aspect of the present invention, in the motion detecting means, H mixed in the one frame difference signal of the composite color television signal in which the HH signal is multiplexed by the identification control signal.
Since the larger one of the first motion coefficient from which the H signal and the chrominance signal have been removed and the second motion coefficient detected with respect to the two-frame difference signal is selected as the motion amount, HH is set in the motion detection area of the luminance signal. It is possible to reduce erroneous detection of motion amount due to leakage of signals and color signals.

According to the third aspect, the one-frame difference detection circuit switches between two types of LPFs having different pass band characteristics by the output of the discrimination control signal decoding circuit, and determines that the high-definition component is multiplexed. In this case, since the pass band of the LPF for extracting the motion component of the luminance signal is narrowed, it is possible to reduce erroneous detection due to the high-definition component and the color signal component leaking into the motion detection region of the luminance signal.

According to the fourth aspect, the one-frame difference detection circuit uses the correlation in the field to limit the horizontal band,
Of the vertical band limitation and the horizontal and vertical two-dimensional band limitation, the band limitation in the direction having the strongest correlation is performed to detect the motion component of the luminance signal, and the identification control signal is used to detect two types of horizontal signals having different pass band characteristics. When the LPF is switched and it is determined that the high-definition components are multiplexed, the pass band of the LPF that extracts the motion component of the luminance signal is narrowed, so that the high-definition component or the color is detected in the movement detection region of the luminance signal. It is possible to reduce erroneous detection due to leakage of signal components.

According to a fifth aspect, in the motion detection circuit, 1
The frame difference signal is divided into a region in which high definition components are mixed and a region in which color signal components are mixed, and a narrow band LPF and color signal components are mixed in a region in which high definition components are mixed. A wide band LPF is used to extract the motion component of the luminance signal in the region.

According to the sixth aspect, similarly to the motion adaptive YC separation filter according to the first aspect, in the motion detecting means, the one-frame difference signal of the composite color television signal in which the HH signal is multiplexed by the identification control signal. H mixed in
Since the H signal and the color signal are removed, it is possible to reduce the erroneous detection of the motion amount due to the HH signal and the color signal leaking into the motion detection area of the luminance signal.

According to a seventh aspect of the invention, like the motion adaptive YC separation filter of the second aspect, in the motion detecting means, one frame difference signal of the composite color television signal in which the HH signal is multiplexed by the identification control signal. H mixed in
Since the larger one of the first motion coefficient from which the H signal and the chrominance signal have been removed and the second motion coefficient detected with respect to the two-frame difference signal is selected as the motion amount, HH is set in the motion detection area of the luminance signal. It is possible to reduce erroneous detection of motion amount due to leakage of signals and color signals.

According to the eighth aspect, as in the motion adaptive YC separation filter according to the third aspect, in the one-frame difference detection circuit, two kinds of LPFs having different pass band characteristics are switched, so that the color signal motion detection area is high. Motion detection can be performed with less false detection due to leakage of fine components and chrominance components, and high-definition components are demodulated and added to the luminance signal. A fine image can be obtained.

According to the ninth aspect, similarly to the motion adaptive YC separation filter according to the fourth aspect, a region for detecting a Y signal motion component is selected from two dimensions, that is, horizontal and vertical, by utilizing the correlation in the field. , 2 with different pass band characteristics
Since the LPFs of different types are switched, motion detection can be performed with few false detections due to leakage of high-definition components and color signal components into the color signal motion detection area, and the high-definition components are demodulated and added to the color signal. , Wide band (0 to 6.3MHz)
It is possible to obtain various color signals.

According to the tenth aspect, similar to the motion adaptive YC separation filter according to the fifth aspect, the one-frame difference signal is separated into a region in which color signal components are mixed and a region in which high-definition components are mixed, respectively. Since horizontal band limitation is performed by two types of LPFs having different pass band characteristics, high-definition components and motion detection can be performed with less erroneous detection due to leakage of high-definition components and color signal components, and high-definition components can be demodulated. Since it is added to the color signal, it is in a wide band (0 to 6.3).
MHz) color signals can be obtained.

According to the eleventh aspect, the signal component in which the motion component of the luminance signal and the high-definition component coexist and the signal component in which the motion component of the luminance signal and the color signal component coexist are obtained in advance, respectively. Since the horizontal band limitation that removes the high-definition component and the color signal component from the 1-frame difference signal of the signal component of is performed, the false detection due to the high-definition component and the color signal component leaking into the motion detection area of the luminance signal Since motion detection can be performed with a small amount and a high-definition component is added to the luminance signal, a luminance signal in a wide band (0 to 6.3 MHz) can be obtained.

[0039]

EXAMPLES Example 1. FIG. 1 is a block diagram showing a motion adaptive YC separation filter according to the first embodiment of the present invention. In the figure, 11 is an identification control signal decoding circuit connected to the input terminal 1, and 82 is a 1-frame difference detection circuit to which the identification control signal from the identification control signal decoding circuit 11 is input. The one-frame difference detection circuit 82 is composed of a subtractor 18a, an HH and C signal removal circuit 20, a C signal removal circuit 21, a selection circuit 22, and an absolute value circuit 23a. Since other parts are the same as the conventional circuit configuration shown in FIG. 16, corresponding parts are designated by the same reference numerals, and the description thereof will be omitted.

Next, the operation of the motion adaptive YC separation filter shown in FIG. 1 will be described. 12 and 13 are diagrams showing the three-dimensional frequency spectrum distribution of the one-frame differential signal obtained by the subtractor 18a. As shown in FIGS. 12 and 13, the HH signal and the C signal are mixed with the Y signal motion component in the one-frame difference signal. from here,
Since only the Y signal motion component is extracted, the output of the subtractor 18a is band-limited by the HH and C signal removing circuit 20 and the C signal removing circuit 21, and the HH signal and the C signal are removed from the 1-frame difference signal. It The identification control signal decoding circuit 11 decodes the identification control signal of the composite color television signal 101, which is transmitted using a specified scan line. This identification control signal is a signal for determining whether or not the HH signal is multiplexed in the composite color television signal 101, and the selection control signal causes the HH and C signal removal circuit 2 in the selection circuit 22 according to the identification control signal.
Either the output of 0 or the output of the C signal removal circuit 21 is selected. That is, the composite color television signal 101
If the HH signal is multiplexed, the band is limited by the HH and C signal removing circuit 20, and if the HH signal is not multiplexed, the band is limited by the C signal removing circuit 21 to obtain the Y signal. H leaked into the motion detection area
The H signal and C signal are removed.

Example 2. FIG. 2 shows a motion adaptive YC separation filter according to a second embodiment of the present invention, and FIG.
FIG. 3 is a block diagram showing a motion detection circuit used in this motion adaptive luminance signal / color signal separation filter. 1 of FIG.
In the frame difference detection circuit 82, 25 is a narrow band LP
F and 26a are wide band LPFs, which are circuits corresponding to the HH and C signal removing circuit 20 and the C signal removing circuit 21 of the first embodiment shown in FIG. 1, respectively. Since the other parts of FIGS. 2 and 3 are the same as the configuration of the motion detection circuit shown in FIG. 1, the corresponding parts are designated by the same reference numerals and the description thereof will be omitted.

In the motion detection circuit 81 of FIG. 3, the one-frame difference signal obtained by the subtractor 18a is band-limited by the narrow band LPF 25 and the wide band LPF 26a. The pass bands of the narrow band LPF 25 and the wide band LPF 26a are designed to be 0 to 1.9 MHz and 0 to 2.1 MHz, respectively. Since the selection circuit 22 selects the output of the narrow band LPF 25 when the HH signals are multiplexed and selects the output of the wide band LPF 26a when the HH signals are not multiplexed, it is shown in FIG. Both the HH signal and the C signal leaked into the Y signal motion component are removed.

Example 3. FIG. 4 is a block diagram showing a motion detection circuit used in the motion adaptive YC separation filter according to the third embodiment of the present invention. This motion detection circuit is used in the motion adaptive luminance signal color signal separation filter of FIG. 2 as in the case of the second embodiment, and is different from the motion detection circuit shown in FIG. 3 in that the narrow band LPF 25. In addition to the wide band LPF 26a, a vertical filter and a two-dimensional filter described below are provided to limit the band of the one-frame differential signal.

In FIG. 4, the one-frame difference signal obtained by the subtractor 18a is band-limited in the horizontal direction by the narrow band LPF 25 and the wide band LPF 26a, and one of the outputs is selected by the selection circuit 22 as in FIG. select. Further, the output of the subtractor 18a is added to the signal delayed by one line in the one-line delay circuit 27a by the adder 28a and further multiplied by ½ in the multiplier 29a, so that the band is limited in the vertical direction. The signal can be output to the selection circuit 30. The output of the selection circuit 22 is further input to the 1-line delay circuit 27b and the adder 28b, and a signal subjected to horizontal and vertical two-dimensional band limitation can be output to the selection circuit 30 from the multiplier 29b. That is, in the selection circuit 30,
The one-frame difference signal subjected to horizontal band limitation, vertical band limitation, and two-dimensional band limitation is input from the selection circuit 22 and the multipliers 29a and 29b, respectively, and the optimum band limitation signal is selected according to the output result of the correlation detection circuit 31. It

FIG. 5 is a block diagram showing an example of the configuration of the correlation detection circuit 31. In the figure, 61 is the horizontal direction C.
A signal decorrelation energy extraction circuit, 62 is a horizontal Y signal decorrelation energy extraction circuit, 63 is a vertical C signal decorrelation energy extraction circuit, 64 is a vertical Y signal decorrelation energy extraction circuit, and 65a to 65j are constants K1.
~ K10 are multipliers, 66a to 66d are maximum value selection circuits, 67a and 67b are comparison circuits, and 68 is a determination circuit.

Next, the operation of the correlation detection circuit 31 will be described. Horizontal C signal decorrelation energy DCH
(Z), the horizontal Y signal decorrelation energy is DYH
(Z), vertical direction C signal decorrelation energy is DCV
(Z), vertical direction Y signal decorrelation energy is DYV
Given (Z), these can be expressed by the following equations. DCH (Z) = | 1-Z- ⁴ | ... (2) DYH (Z) = max {| (1/4). (1 + Z- ¹ ) ^2. (1-Z- ² ) |, | (1 / 4) · (1 + Z ⁻¹ ) ² · (Z ⁻² −Z ⁻⁴ ) |} (3) DCV (Z) = | (1−Z ⁻² ) ² · (1 + Z ^−2L ) |… (4) DYV (Z) = max {| (1/4). (1 + Z- ² ) ^2. (1-Z- ^L ) |, | (1/4). (1 + Z- ² ) ^2. (Z- ^L- Z ^-2L ) |}… (5)

Here, Z ^-1 and Z ^-L are symbols of Z conversion which represent one pixel delay and one line delay, and when the color subcarrier frequency is represented by fsc, Z ^-1 = exp (-j2πf / 4fsc) ) Is. In the NTSC system, fsc = (455 /
2) Since it is fH, L = 910. In the above equations (2) to (5), | A | is an operation that takes the absolute value of A, and max {A, B} is an operation that takes the maximum value of A and B.

The above DCH, DYH, DCV and DYV
Accordingly, the first horizontal decorrelation energy DH1, the second horizontal decorrelation energy DH2, the second vertical decorrelation energy DV2, and the first vertical decorrelation energy DV1 are respectively maximum value selection circuits 66a to 66d.
In, it can be obtained according to the following equations. DH1 = max {K1 · DCH, K2 · DYH} (6) DH2 = max {K9 · DCH, K10 · DYH} (7) DV1 = max {K3 · DCV, K4 · DYV} (8) DV2 = max {K7 · DCV, K8 · DYV} (9) Here, K1, K2, K3, K4, K7, K8, K9,
K10 is a constant.

At this time, in the decision circuit 68, based on the two inputs from the comparison circuits 67a and 67b, (1)
DV1 ≧ K5 · DH2 and DH1 ≧ K6 · DV2 (K
5, K6: constant), it is determined that there is a correlation in the horizontal and vertical directions, and (2) DV1 ≧ K5 · DH2 and DH
When 1 <K6 · DV2, it is determined that there is a correlation only in the horizontal direction, and (3) DV1 <K5 · DH2 and DH1 ≧ K6 ·
When DV2, it is determined that there is a correlation only in the vertical direction,
(4) DV1 <K5 · DH2 and DH1 <K6 · DV2
At this time, it is determined that there is no correlation in the horizontal and vertical directions.

In the correlation detection circuit 31 thus constructed, the output of the selection circuit 30 is controlled as follows according to the detection result of the above correlation. In case of judgment (1),
The horizontal band limited output from the selection circuit 22 is selected. Also in the case of the judgment (2), the horizontal band limited output from the selection circuit 22 is selected. In the case of the determination (3), the vertical band limited signal output from the multiplier 29a is selected. In the case of the judgment (4), the output of the multiplier 29b which is a two-dimensional band limited signal is selected. In the case of the determination (1), either the output limited to the vertical band or the output limited to the two-dimensional band may be selected instead of the output limited to the horizontal band. This is because the frequency spectrum of both the Y signal and the C signal is limited in this case.

Example 4. FIG. 6 is a block diagram showing a motion adaptive YC separation filter according to the fourth embodiment of the present invention. In the figure, 32, 34, 35 and 37 are 26
The two-line delay circuits 33 and 36 are one-line delay circuits. The other parts are basically the same as the configuration of the motion adaptive luminance signal / color signal separation filter shown in FIG. 1, and therefore, corresponding parts are designated by the same reference numerals, and the description thereof will be omitted.

The composite color television signal 101 input to the motion adaptive luminance signal / color signal separation filter is
262 line delay circuits 32 and 34 and 1 line delay circuit 3
The signal delayed by 1 frame at 3 and the subtracter 18a subtract the signal, and a 1-frame differential signal is obtained. Also, input signal 1
The signal obtained by delaying 01 by 262 line by the 262 line delay circuit 32 is the signal delayed by 1 frame by the 1 line delay circuit 33 and the 262 line delay circuits 34 and 35, and the subtracter 1
Subtraction is performed at 8b to obtain a 1-frame difference signal. The 1-frame difference signal from the subtracter 18a and the 1-frame difference signal from the subtractor 18b are delayed by 262 lines from each other. These two difference signals are added by the adder 38 and then 1/2 by the multiplier 40. Doubled. As a result, the components of the second quadrant and the fourth quadrant on the [f-ν] plane in FIG. 13A are extracted from the composite color television signal 101. Further, the output of the multiplier 40 is the wide band LPF 26a.
, The C signal is removed, and the Y signal motion component in the second and fourth quadrants on the [f−ν] plane is extracted.

In addition, the composite color television signal 101
The signal delayed by 263 lines by the 262 line delay circuit 32 and the 1 line delay circuit 33 is subtracted by the subtracter 18c from the signal further delayed by 1 frame by the 262 line delay circuits 34, 35 and the 1 line delay circuit 36. A one-frame differential signal is obtained. The 1-frame difference signal from the subtractor 18a and the 1-frame difference signal from the subtractor 18c are delayed by 263 lines from each other. These two difference signals are added by the adder 39 and then 1/2 by the multiplier 41. Doubled. As a result, the components in the first quadrant and the third quadrant on the [f-ν] plane in FIG. 13A are extracted from the composite color television signal 101. Further, the output of the multiplier 41 is input to the narrow band LPF 25 and the wide band LPF 26b, and is selected by the selection circuit 22. That is, when the HH signal is multiplexed, the band is limited by the narrow band LPF 25, and when the HH signal is not multiplexed, the band is limited by the wide band LPF 26b, [f-ν].
The Y signal motion component in the first and third quadrants on the plane is extracted.

Output of wide band LPF 26a and selection circuit 22
After being added by the adder 42, the output of the absolute value circuit 2
It is converted into an absolute value in 3a, and the motion component of the Y signal is obtained as the output of the 1-frame difference detection circuit 82.

Further, the output of the wide band LPF 26a and the output of the selection circuit 22 are not added by the adder 42, but the larger one of the absolute value outputs is selected by the maximum value circuit, and the motion component of the Y signal is selected. May be obtained.

Example 5. FIG. 7 is a block diagram showing a television signal receiving circuit including a motion adaptive YC separation filter according to the fifth embodiment of the present invention. In the figure, the difference from the motion adaptive luminance signal color signal separation filter of FIG. 1 is that the Y signal 10 after YC separation by the separation filter is performed.
2, the C signal 103 and the further separated and demodulated HH signal 106 from the wideband Y signal 102a and the color difference signal 104,
This is the point where 105 is obtained. In the figure, 43
Is an HH / C separation circuit for separating an HH signal and a C signal, 4
4 is an HH signal demodulation circuit for demodulating the separated HH signal,
Reference numeral 45 is a C signal demodulation circuit for demodulating the separated C signal. The HH signal demodulation circuit 44 is connected to the adder 46 to which the Y signal is input, and the C signal demodulation circuit 45 is connected to the color difference signal 10
4, 105 are output to the output terminals 4 and 5.

The output 103 of the mixing circuit 16a is HH / C.
The HH signal and the C signal are separated by the separation circuit 43, and demodulated by the HH signal demodulation circuit 44 and the C signal demodulation circuit 45, respectively, and the demodulated HH signal 106 and the first and second color difference signals 104 and 105 are obtained. The demodulated HH signal 106 is added to the Y signal 102 output from the subtractor 17 in the adder 46 to obtain the wide band Y signal 102a. By connecting the output terminals 2, 4, and 5 to the image display means, respectively, a high-resolution color screen can be displayed.

Next, a configuration example of the HH / C separation circuit will be described. FIG. 8 is a block diagram showing an example of the HH / C separation circuit 43 for separating the horizontal high definition signal and the color signal. In the figure, 71 is a 262 line delay circuit, 72 is an adder, 73 is a multiplier, 74 is a subtractor,
75 is a switch circuit, and 76 is a selection circuit.

The operation of the HH / C separation circuit 43 will be described below. The signal 103 which is the output of the mixing circuit 16a
Is added to the signal delayed by 262 lines by the 262 line delay circuit 71 by the adder 72, and then 1 / by the multiplier 73.
It is doubled and the components in the second and fourth quadrants on the [f-ν] plane are extracted. The output of the multiplier 73 is subtracted from the signal 103 by the subtractor 74 to obtain the first signal on the [f-ν] plane.
The components of the quadrant and the third quadrant are extracted.

If it is determined by the identification control signal decoding circuit 11 that the HH signals are multiplexed, the input signal 101 contains both the HH signal and the C signal. Therefore, it is necessary to separate each of these signals. Therefore, at this time, the switch circuit 75
Switch is closed (On) and the HH signal demodulation circuit 44
The HH signal is output to. The selection circuit 76 selects the output of the multiplier 73 and outputs the C signal to the C signal demodulation circuit 45. On the contrary, when it is determined that the HH signal is not multiplexed on the input signal 101, the input signal 103 is only the C signal, and thus the HH / C separation process is unnecessary. Therefore, at this time, the switch in the switch circuit 75 is opened (Off), and the input signal 103 is directly output from the selection circuit 76.

Example 6. FIG. 9 is a block diagram showing a television signal receiving circuit according to a sixth embodiment of the present invention. In this television signal receiving circuit, the motion adaptive YC separation filter described in the second embodiment is used. . That is, in the sixth embodiment, the motion detection circuit 81 shown in FIG. 3 is used for the motion adaptive luminance signal / color signal separation filter. The sixth embodiment differs from the second embodiment in that the Y signals 102 and C after YC separation by the separation filter are performed.
Signal 103 and further separated and demodulated HH signal 106
From the wideband Y signal 102a and the color difference signals 104 and 105
Is to improve the resolution of the image.
Since the other parts of FIG. 9 are the same as the configuration of the separation filter shown in FIG. 2, the same reference numerals are given to the corresponding parts and the description thereof will be omitted.

In the motion detection circuit 81, the one-frame difference signal obtained by the subtractor 18a is band-limited by the narrow band LPF 25 and the wide band LPF 26a, as in the third embodiment. Narrow band LPF25, wide band LPF26
The passbands of a are 0 to 1.9 MHz and 0 to 2.1, respectively.
Designed to MHz. Then, the selection circuit 22 selects the output of the narrow band LPF 25 when the HH signals are multiplexed, and the wide band L when the HH signals are not multiplexed.
The output of the PF 26a is selected. In this way, the HH signal and the C signal leaked into the Y signal motion component shown in FIG. 13A are removed, and the motion can be detected with high accuracy. Based on the motion coefficient k detected by the motion detection circuit 81, the mixing circuit 1
The C signal 103 is output from 6a. Its output 103
Is separated into an HH signal and a C signal by an HH / C separation circuit 43 and demodulated by an HH signal demodulation circuit 44 and a C signal demodulation circuit 45, respectively, and the demodulated HH signal 106 and the first and second color difference signals 104 are obtained. , 105 are obtained. The demodulated HH signal 106 is added to the Y signal 102 output from the subtractor 17 in the adder 46 to obtain the wide band Y signal 102a. By connecting the output terminals 2, 4, and 5 to the image display means, respectively, a high-resolution color screen can be displayed.

Example 7. The television signal receiving circuit according to the seventh embodiment of the present invention is as shown in FIG. 4 as the motion detecting circuit 81 of the motion adaptive luminance signal / color signal separation filter of FIG.
The one shown in is used.

The motion adaptive type luminance signal / color signal separation filter using the motion detection circuit 81 of FIG. 4 has already been described in the third embodiment of the present invention. The seventh embodiment differs from the third embodiment in that the wideband Y signal 102a and the color difference signals 104 and 105 are obtained from the Y signal 102 and the C signal 103 after YC separation by the separation filter and the HH signal 106 that is further separated and demodulated. The point is that the resolution of the image is improved. With this, it is possible to obtain the same effects as those described in the sixth embodiment.

Example 8. FIG. 10 is a block diagram showing a television signal receiving circuit according to the eighth embodiment of the present invention. In the figure, the difference from the motion adaptive luminance signal / color signal separation filter of FIG.
Similar to the above, the C signal and the HH signal after YC separation are separated and demodulated to obtain a wide band Y signal and a color difference signal.

Since the motion adaptive luminance signal / chrominance signal separation filter portion of FIG. 10 has the same configuration as the separation filter shown in FIG. 6, corresponding portions are designated by the same reference numerals, and their description will be omitted. .

As in the fourth embodiment, the wide band LPF2
The output of 6a and the output of the selection circuit 22 are not added by the adder 42, but the larger one of the absolute value outputs is selected by the maximum value circuit to obtain the motion component of the Y signal. Good.

Example 9. FIG. 11 is a block diagram showing a television signal receiving circuit including a motion adaptive YC separation filter according to the ninth embodiment of the present invention. In the figure, the difference from the television receiving circuit shown in FIG. 7, FIG. 9 or FIG. 10 is that the input composite color television signal 101 is separated into HH signal and C signal in advance, and then motion detection and YC separation are performed. It is a point. In FIG. 11, 47 is an intra-field filter and 48 is an inter-frame filter.

Input composite color television signal 101
Is subjected to band limitation within the field by the intra-field filter 47, and is subjected to inter-frame calculation by the inter-frame filter 48 with the signal delayed by one frame by the 262 line delay circuits 32 and 34 and the 1-line delay circuit 33.

The input composite color television signal 101 and the signal delayed by one frame are added to the signals delayed by 262 lines by the 262 line delay circuits 32 and 35 by adders 49a and 49b, respectively, and then the multiplier 50a, Fifty
It is multiplied by ½ in b and the motion components in the second and fourth quadrants on the [f−ν] plane are extracted. Multiplier 50a,
The output of 50b is subtracted by the subtractor 55, and the result of FIG.
The components in the second and fourth quadrants of the [f-ν] plane in the above are extracted, and the inter-frame YC separation operation is performed in the field comb filter 13a by the intra-field BPF.
In 12, band limitation in the field is performed. The output of the subtractor 55 is band-limited by the wide band LPF 26a, and the C signal leaking into the motion component of the Y signal is removed.

Further, the input signal 101 and the signal delayed by one frame are 262 line delay circuits 32 and 35, respectively.
Then, the signals delayed by 263 lines in the 1-line delay circuits 33 and 36 are added by the adders 51a and 51b, and then multiplied by ½ in the multipliers 52a and 52b to obtain the first signal on the [f-ν] plane. The motion components in the quadrant and the third quadrant are extracted. Multiplier 5
The outputs of 2a and 52b are subtracted by the subtractor 56, and
The motion components in the first quadrant and the third quadrant of the [f-ν] plane in 3 (a) are extracted, and the interframe calculation is performed in the frame comb filter 13b. Subtractor 5
The outputs of 6 are narrow band LPF 25 and wide band LPF 26.
Band-limited by b. When the identification control signal decoding circuit 11 determines that the HH signals are multiplexed, the selection circuit 22 performs band limitation by the narrow band LPF 25,
If it is determined that the HH signals are not multiplexed, the band is limited by the wide band LPF 26a to remove the HH signal and the C signal leaking into the Y signal motion component. The output of the broadband LPF 26a and the output of the selection circuit 22 are added by the adder 4
After being added in 2, it is converted into an absolute value in the absolute value circuit 23a to obtain the motion component of the Y signal. In addition, the broadband LPF 26
The output of a and the output of the selection circuit 22 are not added by the adder 42, but the larger one of the absolute value outputs is selected by the maximum value circuit to obtain the motion component of the Y signal. Good.

The mixing circuits 16a and 16b are the motion detecting circuit 8
It is controlled by the output of 1 to obtain the Y signal and the C signal, respectively. The C signal is color demodulated by the C demodulation circuit 45, and the first,
The second color difference signals 104 and 105 are output. Multiplier 53
Is controlled to increase the value of the motion coefficient k when the image is a still image and to decrease the value of k when the image is a moving image, according to the output result of the motion detection circuit 81. However, the range of values of the motion coefficient k is 0 ≦ k ≦ 1. Multiplier 53
Is demodulated by the HH demodulation circuit 44 and a demodulated HH signal is output. The demodulated HH signal is set to H by the switch circuit 54.
If it is determined that the H signals are multiplexed, the switch is turned on and the adder 46 adds the Y signals to obtain the wide band luminance signal 102.

[0073]

According to the first aspect of the present invention, the detection method in motion detection is switched depending on whether or not the high-definition component is multiplexed in the composite color television signal. A motion adaptive luminance signal / color signal separation filter capable of preventing erroneous detection such as erroneous recognition can be provided. As a result, crosstalk can be reduced.

According to the second aspect of the invention, the detection method in the motion detection is switched depending on whether or not the high-definition component is multiplexed in the composite color television signal to detect the first motion coefficient, and the second motion coefficient is detected. Since a large amount is selected as the amount of motion from the motion coefficient of, the motion adaptive luminance signal color signal separation filter that prevents false detection such that the high definition component is mistakenly recognized as the motion component is Can be provided. As a result, crosstalk can be reduced.

According to the third aspect of the invention, in the motion detecting circuit, when high-definition components are multiplexed by filtering with LPFs having different pass bands,
Since the motion is detected by the LPF having a narrow pass band, it is possible to provide a motion adaptive luminance signal color signal separation filter which prevents erroneous detection of recognizing a high definition component as a motion component of the luminance signal. As a result, crosstalk can be reduced.

According to the fourth aspect of the present invention, in the motion detection circuit, the high-definition components are multiplexed by filtering with LPFs having different pass bands depending on whether or not the high-definition components are multiplexed. In addition, since the motion is detected by the LPF having a narrow pass band, it is possible to provide a motion adaptive luminance signal / color signal separation filter that prevents erroneous detection of recognizing a high definition component as a motion component. Further, the optimum one of the horizontal, vertical, and two-dimensional filters is configured as a filter that receives the one-frame differential signal according to the spatial correlation of the image, so that more accurate motion detection can be performed. .

According to the fifth aspect of the invention, in the one-frame difference detection circuit, the one-frame difference signal is separated into a region in which color signal components are mixed and a region in which high-definition components are mixed, and the pass bands are respectively separated. By performing horizontal band limitation by two types of LPFs having different characteristics, it is possible to reduce erroneous detection due to leakage of high-definition components and chrominance signal components into the motion detection area of the luminance signal, so that each composite color television It is possible to provide a motion adaptive type luminance signal / color signal separation filter capable of detecting a motion matching a signal characteristic.

According to the invention of claim 6, the detection method in the motion detection is switched depending on whether or not the high-definition component is multiplexed in the composite color television signal.
It is possible to provide a television signal receiving circuit that prevents erroneous detection such that a high definition component is erroneously recognized as a motion component. As a result, it is possible to reduce crosstalk and reproduce an image with little deterioration in image quality.

According to the invention of claim 7, the detection method in the motion detection is switched depending on whether or not the high-definition component is multiplexed in the composite color television signal to detect the first motion coefficient, and the second motion coefficient is detected. Therefore, a television signal receiving circuit can be provided that prevents erroneous detection such that a high-definition component is erroneously recognized as a motion component because a large amount is selected as the motion amount. As a result, it is possible to reduce crosstalk and reproduce an image with little deterioration in image quality.

According to the eighth aspect of the present invention, in the motion detection circuit, the high-definition components are multiplexed by filtering with LPFs having different pass bands depending on whether or not the high-definition components are multiplexed. In addition, since the motion is detected by the LPF having a narrow pass band, it is possible to provide a television signal receiving circuit that prevents erroneous detection of recognizing a high definition component as a motion component. Further, as a result, crosstalk can be reduced, and since the demodulated high-definition component is added to the luminance signal, a luminance signal with a wide bandwidth can be obtained.

According to the ninth aspect of the present invention, in the motion detection circuit, high-definition components are multiplexed by filtering with LPFs having different pass bands depending on whether or not the high-definition components are multiplexed. In addition, since the motion is detected by the LPF having a narrow pass band, it is possible to provide a television signal receiving circuit that prevents erroneous detection of recognizing a high definition component as a motion component. Further, according to the spatial correlation of the image, the most suitable one among the horizontal, vertical and two-dimensional filters is used as the filter having the 1-frame difference signal as an input, so that more accurate motion detection can be performed, Further, since the demodulated high-definition component is added to the color signal, a color signal with a wide band can be obtained.

According to the tenth aspect of the invention, in the motion detecting circuit, one frame difference signal is divided into a region in which high-definition components are mixed and a region in which color signal components are mixed, and The narrow band LPF is extracted in the mixed area and the wide band LPF is extracted in the mixed area of the color signal component, so that the motion detection matching the characteristics of each signal can be performed. Since the demodulated high-definition component is added to the color signal, it is possible to provide a television signal receiving circuit capable of obtaining a color signal with a wide band.

According to the eleventh aspect of the present invention, the input signal is divided into a region in which the high-definition components are multiplexed in advance and a region in which the color signal components are multiplexed, and a region in which the high-definition components are mixed. Since a narrow band LPF is extracted to the area, and a wide band LPF extracts the motion component of the luminance signal to the area where the color signal components are mixed, a television signal reception that enables motion detection matching the characteristics of each signal A circuit can be provided. Moreover, since the demodulated high-definition component is added to the luminance signal, a luminance signal with a wide band can be obtained. Furthermore, since the high-definition component and the color signal component are separated in advance, the HH / C separation circuit can be omitted, and the field memory used for the HH / C separation circuit becomes unnecessary.

[Brief description of drawings]

FIG. 1 is a block diagram showing a configuration of a motion adaptive luminance signal / color signal separation filter according to a first embodiment.

FIG. 2 is a block diagram showing a configuration of a motion adaptive luminance signal / color signal separation filter according to a second embodiment.

FIG. 3 is a block diagram showing a configuration of a motion detection circuit in a motion adaptive luminance signal / color signal separation filter according to a second embodiment.

FIG. 4 is a block diagram showing a configuration of a motion detection circuit in a motion adaptive luminance signal / color signal separation filter according to a third embodiment.

FIG. 5 is a block diagram showing an example of a correlation detection circuit in a motion adaptive luminance signal color signal separation filter according to a third embodiment.

FIG. 6 is a block diagram showing a configuration of a motion adaptive luminance signal / color signal separation filter according to a fourth embodiment.

FIG. 7 is a block diagram showing a configuration of a television signal receiving circuit according to a fifth embodiment.

FIG. 8 is a block diagram illustrating an example of a high definition signal color signal separation circuit according to a fifth embodiment.

FIG. 9 is a block diagram showing a configuration of a television signal receiving circuit according to a sixth embodiment and a seventh embodiment.

FIG. 10 is a block diagram showing a configuration of a television signal receiving circuit according to an eighth embodiment.

FIG. 11 is a block diagram showing a configuration of a television signal receiving circuit according to a ninth embodiment.

FIG. 12 is a spectrum distribution diagram of a one-frame differential signal of a composite color television signal in a three-dimensional frequency space.

13A is a diagram showing a spectral distribution of a one-frame differential signal of a composite color television signal in a three-dimensional frequency space, FIG. 13A is a diagram viewed from the positive direction of the μ axis, and FIG. 13B is a projection diagram on the μ axis. .

FIG. 14: Y signal and C in three-dimensional frequency space
It is a spectrum distribution diagram of a signal and an HH signal.

FIG. 15: Y signal and C in three-dimensional frequency space
(A) is a diagram of the spectral distributions of the signal and the HH signal as seen from the positive direction of the μ axis, and (b) is a projection diagram on the μ axis.

FIG. 16 is a block diagram showing a configuration of a conventional motion adaptive luminance signal / color signal separation filter.

FIG. 17A is a spectrum distribution diagram of Y signals, C signals, and HH signals in a three-dimensional frequency space;
(B) is a view seen from the positive direction of the μ axis, and (c) is a projection view onto the μ axis.

[Explanation of symbols]

1 input terminal, 2 Y signal output terminal, 3 C signal and HH signal output terminal, 4, 5 color difference signal output terminal, 11
Identification control signal decoding circuit, 12 intra-field band pass filter, 13a, 13b frame comb filter, 1
4, 15 1 frame delay circuit, 16a, 16b mixing circuit, 17, 18a to 18c, 19, 55, 56 subtractor, 20 HH and C signal removing circuit, 21 HH and C signal removing circuit, 22, 30 selection circuit, 23a, 2
3b absolute value circuit, 24 maximum value selection circuit, 25 narrow band LPF, 26a, 26b wide band LPF, 27a, 2
7b 1-line delay circuit, 28a, 28b, 38, 3
9, 42, 46, 49a, 49b, 51a, 51b Adder, 29a, 29b, 40, 41, 50a, 50b,
52a, 52b, 53 Multiplier, 31 Correlation detection circuit,
32, 34, 35, 37 262 line delay circuit, 43
HH / C separation circuit, 44 HH demodulation circuit, 45 C demodulation circuit, 47 intra-field filter, 48 inter-frame filter, 54 switch circuit, 55 LPF, 81
Motion detection circuit, 82 1-frame difference detection circuit, 83
Two-frame difference detection circuit.

Front page continuation (72) Inventor Akira Okumura 1 Baba Zoujo Nagaokakyo, Kyoto Prefecture Mitsubishi Electric Corporation Video System Development Laboratory (56) Reference JP-A-6-38236 (JP, A) JP-A-6 -292226 (JP, A) JP-A-6-189219 (JP, A) JP-A-6-164994 (JP, A) (58) Fields investigated (Int.Cl. ⁷ , DB name) H04N 9/78 H04N 7/015

Claims (11)

(57) [Claims] 1. A motion adaptive luminance signal for YC separating a luminance signal and a color signal from a composite color television signal (high-definition television signal) in which a horizontal high-definition signal (hereinafter referred to as HH signal) is multiplexed. In the color signal separation filter, an identification control signal decoding means for decoding an identification control signal for identifying whether or not the input signal is a high definition television signal, the identification control signal decoding means decoding the signal transmitted together with the composite color television signal, A frame comb that performs YC separation calculation between frames between an intra-field band pass filter that performs YC separation calculation in the field by band-pass filtering processing of a composite color television signal and two composite color television signals that have a time difference of 1 frame. Type filter and the above composite color if the input signal is a high definition television signal. The HH signal and the chrominance signal is removed from the revision signal, as otherwise removes the color signal component from said composite color television signal, the band in the horizontal direction of the frequency components by the decoded identification control signal
The motion detection means for detecting the motion amount of the composite color television signal by switching the pass band to be limited, the in- field band pass filter and the operation result of the frame comb filter are mixed based on the motion amount. A motion adaptive luminance signal color signal separation filter comprising mixing means and subtraction means for subtracting the output of the mixing means from the composite color television signal to output a luminance signal. 2. A 1-frame difference detection circuit for detecting a first motion coefficient for a 1-frame difference signal from two composite color television signals having a 1-frame time difference, and a 2-frame time difference. A two-frame difference detection circuit for detecting a second motion coefficient for a two-frame difference signal from two composite color television signals having a certain number, and a larger one of the first and second motion coefficients is selected as the motion amount. The motion adaptive luminance signal / chrominance signal separation filter according to claim 1, further comprising a maximum value selection circuit for 3. The 1-frame difference detection circuit includes a difference calculation circuit for calculating the 1-frame difference signal, and a horizontal low-frequency filter whose pass band is set so as to remove the HH signal and the color signal from the 1-frame difference signal. A low pass filter (hereinafter referred to as a narrow band LPF) and a horizontal low pass filter (hereinafter referred to as a wide band LPF) in which a pass band different from the narrow band LPF is set so as to remove a color signal from the 1-frame difference signal. .) And the input signal is a high definition television signal, the output of the narrow band LPF is selected as the first motion coefficient,
The motion adaptive luminance signal chrominance signal separation filter according to claim 2, further comprising: a selection circuit that selects the output of the wide band LPF as the first motion coefficient. 4. The one-frame difference detection circuit, a correlation detection circuit for detecting a horizontal correlation and a vertical correlation of the composite color television signal; a difference calculation circuit for calculating the one-frame difference signal; A horizontal low-pass filter (hereinafter referred to as a narrow band LPF) having a pass band set so as to remove the HH signal and the color signal from the frame difference signal, and the above so as to remove the color signal from the one frame difference signal. narrowband LPF different pass band is set horizontal low-pass filter (hereinafter, referred to as wideband LPF.), and vertical low-pass filter for band-limiting the 1 frame difference signal for a frequency component in the vertical direction, the A two-dimensional low-pass filter that band-limits one-frame differential signal for horizontal and vertical frequency components, and high-definition input signal In the case of a revision signal, of the outputs of the narrow band LPF, the vertical low pass filter or the two-dimensional low pass filter, the amount of motion in the direction in which the correlation is strong by the correlation detection circuit is used as the first motion coefficient. Otherwise, of the outputs of the wide band LPF, the vertical low pass filter or the two-dimensional low pass filter, the amount of motion in the direction in which the correlation is strong is selected by the correlation detection circuit as the first motion coefficient. 3. The motion adaptive luminance signal / chrominance signal separation filter according to claim 2, further comprising: 5. The one-frame difference detection circuit comprises a difference calculation circuit for calculating the one-frame difference signal, the one-frame difference signal, and two one-frame difference signals delayed by one field, respectively. color television signal of the time - at the vertical frequency space
Signal areas in the second and fourth quadrants in which color signals are mixed and HH
First extraction means for extracting a signal area of the third quadrant, the 1 frame difference signal of a signal area in which the color signal are mixed by a horizontal band-limited, time signals are mixed - the second vertical frequency space, Fourth
The first horizontal low-pass filter for obtaining the motion component in the quadrant and the one-frame differential signal in the signal area in which the HH signals are mixed are subjected to horizontal band limitation, and the motion in the first and third quadrants of the time-vertical frequency space A second horizontal low-pass filter for obtaining a component; and an adder circuit for adding the motion components of the first and second horizontal low-pass filters and outputting the sum as the first motion amount. The motion adaptive type luminance signal / color signal separation filter according to claim 2. 6. A television signal for receiving a composite color television signal (high-definition television signal) in which a horizontal high-definition signal (hereinafter referred to as HH signal) is multiplexed to obtain a broadband luminance signal and a color signal. In the receiving circuit, an identification control signal for identifying whether or not the input signal is a high-definition television signal, and an identification control signal decoding means for decoding a signal transmitted together with the composite color television signal; An intra-field band pass filter that performs an intra-field YC separation calculation by band-pass filtering processing of a television signal, and a frame comb filter that performs an inter-frame YC separation calculation between two composite color television signals with a time difference of 1 frame. If the input signal is a high definition television signal, The HH signal and the chrominance signal is removed from the tone signal, as otherwise removes the color signal component from said composite color television signal, the band in the horizontal direction of the frequency components by the decoded identification control signal
The motion detection means for detecting the motion amount of the composite color television signal by switching the pass band to be limited, the in- field band pass filter and the operation result of the frame comb filter are mixed based on the motion amount. Mixing means, subtracting means for subtracting the output of the mixing means from the composite color television signal to output a luminance signal, separating means for separating the color signal and the HH signal from the output of the mixing means, and the separating means. Demodulating means for demodulating the HH signal separated by the above, and color demodulating means for demodulating the color signal components separated by the separating means to output first and second color difference signals; And a adding means for adding the HH signals and outputting a broadband luminance signal. 7. The motion detecting means comprises a 1-frame difference detection circuit for detecting a first motion coefficient for a 1-frame difference signal from two composite color television signals having a 1-frame time difference, and a 2-frame time difference. A two-frame difference detection circuit for detecting a second motion coefficient for a one-frame difference signal from two composite color television signals having a certain number, and a larger one of the first and second motion coefficients is selected as the motion amount. 7. The television signal receiving circuit according to claim 6, further comprising: a maximum value selecting circuit. 8. The one-frame difference detection circuit includes a difference calculation circuit for calculating the one-frame difference signal, and a horizontal low frequency band whose pass band is set so as to remove the HH signal and the color signal from the one-frame difference signal. A low pass filter (hereinafter referred to as a narrow band LPF) and a horizontal low pass filter (hereinafter referred to as a wide band LPF) in which a pass band different from the narrow band LPF is set so as to remove a color signal from the 1-frame difference signal. .) And the input signal is a high definition television signal, the output of the narrow band LPF is selected as the first motion coefficient,
8. The television signal receiving circuit according to claim 7, further comprising a selection circuit that selects the output of the wide band LPF as the first motion coefficient. 9. The one-frame difference detection circuit, a correlation detection circuit for detecting the correlation in the horizontal and vertical directions of the composite color television signal, a difference calculation circuit for calculating the one-frame difference signal, A horizontal low-pass filter (hereinafter referred to as a narrow band LPF) having a pass band set so as to remove the HH signal and the color signal from the frame difference signal, and the above so as to remove the color signal from the one frame difference signal. A horizontal low pass filter (hereinafter referred to as a wide band LPF) in which a pass band different from that of the narrow band LPF is set; a vertical low pass filter for band limiting the one frame difference signal with respect to a frequency component in the vertical direction; A two-dimensional low-pass filter that limits the band of the frame difference signal with respect to the frequency components in the horizontal and vertical directions. In the case of a revision signal, of the outputs of the narrow band LPF, the vertical low pass filter or the two-dimensional low pass filter, the amount of motion in the direction in which the correlation is strong by the correlation detection circuit is used as the first motion coefficient. Otherwise, of the outputs of the wide band LPF, the vertical low pass filter or the two-dimensional low pass filter, the amount of motion in the direction in which the correlation is strong is selected by the correlation detection circuit as the first motion coefficient. 8. The television signal receiving circuit according to claim 7, further comprising: 10. The one-frame difference detection circuit comprises a difference calculation circuit for calculating the one-frame difference signal, the one-frame difference signal, and two one-frame difference signals delayed by one field, respectively. color television signal of the time - at the vertical frequency space
Signal areas in the second and fourth quadrants in which color signals are mixed and HH
First extraction means for extracting a signal area of the third quadrant, the 1 frame difference signal of a signal area in which the color signal are mixed by a horizontal band-limited, time signals are mixed - the second vertical frequency space, Fourth
The first horizontal low-pass filter for obtaining the motion component in the quadrant and the one-frame differential signal in the signal area in which the HH signals are mixed are subjected to horizontal band limitation, and the motion in the first and third quadrants of the time-vertical frequency space A second horizontal low-pass filter for obtaining a component; and an adder circuit for adding the motion components of the first and second horizontal low-pass filters and outputting the sum as the first motion amount. The television signal receiving circuit according to claim 7. 11. A television signal for receiving a composite color television signal (high-definition television signal) in which a horizontal high-definition signal (hereinafter referred to as HH signal) is multiplexed to obtain a broadband luminance signal and a color signal. In the receiving circuit, an identification control signal for identifying whether or not the input signal is a high-definition television signal, the identification control signal decoding means for decoding a signal transmitted together with the composite color television signal; An intra-field filter that performs band-pass filtering on a John signal, an inter-frame filter that calculates two composite color television signals with a time difference of one frame, and two composite color television signals with a time difference of one field First to extract a signal domain component in which a color signal is mixed in a time-vertical frequency space It means out from two composite color television signal with a time difference of one field, the time - HH in the vertical frequency space
Second extracting means for extracting a signal region component in which signals are mixed, an in-field band pass filter for performing an in-field YC separation operation by performing band pass filtering processing on the output of the first extracting means, A first frame comb filter for performing an inter-frame YC separation operation between two composite color television signals having a time difference of one frame extracted from the extraction means, and 1 extracted from the second extraction means. A second frame comb filter for performing YC separation calculation between frames between two composite color television signals having a frame time difference, and a time difference of one frame extracted from the first and second extraction means. Arithmetic means for computing the difference between certain two composite color television signals, and horizontal band limitation of the signal area component in which the color signals are mixed. Then, the first horizontal low-pass filter for obtaining the motion component in the second and fourth quadrants of the time-vertical frequency space and the horizontal band limitation of the signal area component in which the HH signal are mixed are performed to obtain the time-vertical frequency. A second horizontal low-pass filter for obtaining a motion component in the first and third quadrants of the space and the motion components by the first and second horizontal low-pass filters are added and output as a first motion amount. First adding means, a two-frame difference detection circuit for detecting a second motion amount for a two-frame difference signal from two composite color television signals having a two-frame time difference, and the first and second motions described above. A maximum value selecting means for selecting a larger one of the amounts as a motion coefficient, and a first mixing for mixing the output of the intra-field filter and the output of the inter-frame filter based on the motion coefficient. A second mixing means for mixing the output of the in-field bandpass filter and the output of the first frame comb filter based on the motion coefficient; the output of the second frame comb filter; Multiplying means for multiplying with the motion coefficient to generate a high-definition component, color demodulating means for color demodulating the first and second color difference signals from the output of the second mixing means, and output of the multiplying means. It is characterized by comprising demodulation means for demodulating the HH signal, and second addition means for adding the HH signal demodulated by the demodulation means to the output of the first mixing means to output a wide band luminance signal. Television signal receiving circuit.